1. Field of the Invention
The present invention relates to a display apparatus and, more particularly, to a TFT substrate, a method of manufacturing the TFT substrate and a display apparatus having the TFT substrate.
2. Description of the Related Art
Recently, flat panel display apparatus, such as the organic light-emitting display (OLED), the plasma display panel (PDPs) and the liquid crystal display (LCD) have been developed to substitute for heavy and large cathode ray tube (CRT) displays. The PDP apparatus displays images using plasma generated by an electric discharge. The OLED apparatus displays images and characters using organic electroluminescence of a specific organic material and a polymer. The LCD apparatus displays images by controlling the transmissivity of light passing through a liquid crystal layer.
In general, the LCD apparatus includes a thin-film transistor (TFT) substrate, a common electrode substrate and a liquid crystal layer disposed between the TFT substrate and the common electrode substrate. When the TFT substrate and the common electrode substrate are misaligned during the manufacturing process for the LCD apparatus, the display quality of the LCD apparatus is adversely affected.
In order to prevent the display quality from being affected by the misalignment, a color filter on array (COA) structure may be employed in which a color filter is disposed on the TFT substrate. However, impurities from the color filter may elute through a gap or an opening between pixel electrodes, contaminate the liquid crystal and cause an afterimage to be displayed.
Furthermore, when an organic insulating layer is used as a planarization layer under the pixel electrode, impurities from the organic insulating layer elute. As a result, the liquid crystal is also contaminated, and the afterimage increases.